The day marks the one month anniversary of the mass shooting that left 17 dead at Marjory Stoneman Douglas High School in Parkland, Florida. Protestors in Washington D.C. even walked up to the front of the White House to demonstrate their determination for change. Here are some of the most powerful signs from the march.

Today, 1 month after of the day that changed our lives forever, we will join the school walkout. We will join the walkout for every one of those 17, and for every other victim of gun violence. We will join for those that are still here. We will join for you. #NeverAgain

Administrators at Booker T. Washington High School in Atlanta threatened to punish students who participated in walkouts. The school was even put on lockdown to prevent students from leaving. Still, they participated in the protest by silently kneeling in the school’s hallways.